[flash_ctrl] Fix leaky permission
[flash_ctrl] Fix leaky permission

Permission control was criscrossing between rd/prog/erase/bk_erase
Fix so that each is qualified with the related request.

lowRISC/opentitan,lowRISC/opentitan,lowRISC/opentitan,lowRISC/opentitan,lowRISC/opentitan,lowRISC/opentitan